%% Copyright (c) 2011-2014, Loïc Hoguin <[email protected]>
%% Copyright (c) 2011, Anthony Ramine <[email protected]>
%%
%% Permission to use, copy, modify, and/or distribute this software for any
%% purpose with or without fee is hereby granted, provided that the above
%% copyright notice and this permission notice appear in all copies.
%%
%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
%% @doc HTTP protocol handler.
%%
%% The available options are:
%% <dl>
%% <dt>compress</dt><dd>Whether to automatically compress the response
%% body when the conditions are met. Disabled by default.</dd>
%% <dt>env</dt><dd>The environment passed and optionally modified
%% by middlewares.</dd>
%% <dt>max_empty_lines</dt><dd>Max number of empty lines before a request.
%% Defaults to 5.</dd>
%% <dt>max_header_name_length</dt><dd>Max length allowed for header names.
%% Defaults to 64.</dd>
%% <dt>max_header_value_length</dt><dd>Max length allowed for header values.
%% Defaults to 4096.</dd>
%% <dt>max_headers</dt><dd>Max number of headers allowed.
%% Defaults to 100.</dd>
%% <dt>max_keepalive</dt><dd>Max number of requests allowed in a single
%% keep-alive session. Defaults to 100.</dd>
%% <dt>max_request_line_length</dt><dd>Max length allowed for the request
%% line. Defaults to 4096.</dd>
%% <dt>middlewares</dt><dd>The list of middlewares to execute when a
%% request is received.</dd>
%% <dt>onrequest</dt><dd>Optional fun that allows Req interaction before
%% any dispatching is done. Host info, path info and bindings are thus
%% not available at this point.</dd>
%% <dt>onresponse</dt><dd>Optional fun that allows replacing a response
%% sent by the application.</dd>
%% <dt>timeout</dt><dd>Time in milliseconds a client has to send the
%% full request line and headers. Defaults to 5000 milliseconds.</dd>
%% </dl>
%%
%% Note that there is no need to monitor these processes when using Cowboy as
%% an application as it already supervises them under the listener supervisor.
-module(cowboy_protocol).
%% API.
-export([start_link/4]).
%% Internal.
-export([init/4]).
-export([parse_request/3]).
-export([resume/6]).
-type opts() :: [{compress, boolean()}
| {env, cowboy_middleware:env()}
| {max_empty_lines, non_neg_integer()}
| {max_header_name_length, non_neg_integer()}
| {max_header_value_length, non_neg_integer()}
| {max_headers, non_neg_integer()}
| {max_keepalive, non_neg_integer()}
| {max_request_line_length, non_neg_integer()}
| {middlewares, [module()]}
| {onrequest, cowboy:onrequest_fun()}
| {onresponse, cowboy:onresponse_fun()}
| {timeout, timeout()}].
-export_type([opts/0]).
-record(state, {
socket :: inet:socket(),
transport :: module(),
middlewares :: [module()],
compress :: boolean(),
env :: cowboy_middleware:env(),
onrequest :: undefined | cowboy:onrequest_fun(),
onresponse = undefined :: undefined | cowboy:onresponse_fun(),
max_empty_lines :: non_neg_integer(),
req_keepalive = 1 :: non_neg_integer(),
max_keepalive :: non_neg_integer(),
max_request_line_length :: non_neg_integer(),
max_header_name_length :: non_neg_integer(),
max_header_value_length :: non_neg_integer(),
max_headers :: non_neg_integer(),
timeout :: timeout(),
until :: non_neg_integer() | infinity
}).
-include_lib("cowlib/include/cow_inline.hrl").
%% API.
%% @doc Start an HTTP protocol process.
-spec start_link(ranch:ref(), inet:socket(), module(), opts()) -> {ok, pid()}.
start_link(Ref, Socket, Transport, Opts) ->
Pid = spawn_link(?MODULE, init, [Ref, Socket, Transport, Opts]),
{ok, Pid}.
%% Internal.
%% @doc Faster alternative to proplists:get_value/3.
%% @private
get_value(Key, Opts, Default) ->
case lists:keyfind(Key, 1, Opts) of
{_, Value} -> Value;
_ -> Default
end.
%% @private
-spec init(ranch:ref(), inet:socket(), module(), opts()) -> ok.
init(Ref, Socket, Transport, Opts) ->
Compress = get_value(compress, Opts, false),
MaxEmptyLines = get_value(max_empty_lines, Opts, 5),
MaxHeaderNameLength = get_value(max_header_name_length, Opts, 64),
MaxHeaderValueLength = get_value(max_header_value_length, Opts, 4096),
MaxHeaders = get_value(max_headers, Opts, 100),
MaxKeepalive = get_value(max_keepalive, Opts, 100),
MaxRequestLineLength = get_value(max_request_line_length, Opts, 4096),
Middlewares = get_value(middlewares, Opts, [cowboy_router, cowboy_handler]),
Env = [{listener, Ref}|get_value(env, Opts, [])],
OnRequest = get_value(onrequest, Opts, undefined),
OnResponse = get_value(onresponse, Opts, undefined),
Timeout = get_value(timeout, Opts, 5000),
ok = ranch:accept_ack(Ref),
wait_request(<<>>, #state{socket=Socket, transport=Transport,
middlewares=Middlewares, compress=Compress, env=Env,
max_empty_lines=MaxEmptyLines, max_keepalive=MaxKeepalive,
max_request_line_length=MaxRequestLineLength,
max_header_name_length=MaxHeaderNameLength,
max_header_value_length=MaxHeaderValueLength, max_headers=MaxHeaders,
onrequest=OnRequest, onresponse=OnResponse,
timeout=Timeout, until=until(Timeout)}, 0).
-spec until(timeout()) -> non_neg_integer() | infinity.
until(infinity) ->
infinity;
until(Timeout) ->
{Me, S, Mi} = os:timestamp(),
Me * 1000000000 + S * 1000 + Mi div 1000 + Timeout.
%% Request parsing.
%%
%% The next set of functions is the request parsing code. All of it
%% runs using a single binary match context. This optimization ends
%% right after the header parsing is finished and the code becomes
%% more interesting past that point.
-spec recv(inet:socket(), module(), non_neg_integer() | infinity)
-> {ok, binary()} | {error, closed | timeout | atom()}.
recv(Socket, Transport, infinity) ->
Transport:recv(Socket, 0, infinity);
recv(Socket, Transport, Until) ->
{Me, S, Mi} = os:timestamp(),
Now = Me * 1000000000 + S * 1000 + Mi div 1000,
Timeout = Until - Now,
if Timeout < 0 ->
{error, timeout};
true ->
Transport:recv(Socket, 0, Timeout)
end.
-spec wait_request(binary(), #state{}, non_neg_integer()) -> ok.
wait_request(Buffer, State=#state{socket=Socket, transport=Transport,
until=Until}, ReqEmpty) ->
case recv(Socket, Transport, Until) of
{ok, Data} ->
parse_request(<< Buffer/binary, Data/binary >>, State, ReqEmpty);
{error, _} ->
terminate(State)
end.
%% @private
-spec parse_request(binary(), #state{}, non_neg_integer()) -> ok.
%% Empty lines must be using \r\n.
parse_request(<< $\n, _/binary >>, State, _) ->
error_terminate(400, State);
%% We limit the length of the Request-line to MaxLength to avoid endlessly
%% reading from the socket and eventually crashing.
parse_request(Buffer, State=#state{max_request_line_length=MaxLength,
max_empty_lines=MaxEmpty}, ReqEmpty) ->
case match_eol(Buffer, 0) of
nomatch when byte_size(Buffer) > MaxLength ->
error_terminate(414, State);
nomatch ->
wait_request(Buffer, State, ReqEmpty);
1 when ReqEmpty =:= MaxEmpty ->
error_terminate(400, State);
1 ->
<< _:16, Rest/binary >> = Buffer,
parse_request(Rest, State, ReqEmpty + 1);
_ ->
parse_method(Buffer, State, <<>>)
end.
match_eol(<< $\n, _/bits >>, N) ->
N;
match_eol(<< _, Rest/bits >>, N) ->
match_eol(Rest, N + 1);
match_eol(_, _) ->
nomatch.
parse_method(<< C, Rest/bits >>, State, SoFar) ->
case C of
$\r -> error_terminate(400, State);
$\s -> parse_uri(Rest, State, SoFar);
_ -> parse_method(Rest, State, << SoFar/binary, C >>)
end.
parse_uri(<< $\r, _/bits >>, State, _) ->
error_terminate(400, State);
parse_uri(<< "* ", Rest/bits >>, State, Method) ->
parse_version(Rest, State, Method, <<"*">>, <<>>);
parse_uri(<< "http://", Rest/bits >>, State, Method) ->
parse_uri_skip_host(Rest, State, Method);
parse_uri(<< "https://", Rest/bits >>, State, Method) ->
parse_uri_skip_host(Rest, State, Method);
parse_uri(Buffer, State, Method) ->
parse_uri_path(Buffer, State, Method, <<>>).
parse_uri_skip_host(<< C, Rest/bits >>, State, Method) ->
case C of
$\r -> error_terminate(400, State);
$/ -> parse_uri_path(Rest, State, Method, <<"/">>);
_ -> parse_uri_skip_host(Rest, State, Method)
end.
parse_uri_path(<< C, Rest/bits >>, State, Method, SoFar) ->
case C of
$\r -> error_terminate(400, State);
$\s -> parse_version(Rest, State, Method, SoFar, <<>>);
$? -> parse_uri_query(Rest, State, Method, SoFar, <<>>);
$# -> skip_uri_fragment(Rest, State, Method, SoFar, <<>>);
_ -> parse_uri_path(Rest, State, Method, << SoFar/binary, C >>)
end.
parse_uri_query(<< C, Rest/bits >>, S, M, P, SoFar) ->
case C of
$\r -> error_terminate(400, S);
$\s -> parse_version(Rest, S, M, P, SoFar);
$# -> skip_uri_fragment(Rest, S, M, P, SoFar);
_ -> parse_uri_query(Rest, S, M, P, << SoFar/binary, C >>)
end.
skip_uri_fragment(<< C, Rest/bits >>, S, M, P, Q) ->
case C of
$\r -> error_terminate(400, S);
$\s -> parse_version(Rest, S, M, P, Q);
_ -> skip_uri_fragment(Rest, S, M, P, Q)
end.
parse_version(<< "HTTP/1.1\r\n", Rest/bits >>, S, M, P, Q) ->
parse_header(Rest, S, M, P, Q, 'HTTP/1.1', []);
parse_version(<< "HTTP/1.0\r\n", Rest/bits >>, S, M, P, Q) ->
parse_header(Rest, S, M, P, Q, 'HTTP/1.0', []);
parse_version(_, State, _, _, _) ->
error_terminate(505, State).
%% Stop receiving data if we have more than allowed number of headers.
wait_header(_, State=#state{max_headers=MaxHeaders}, _, _, _, _, Headers)
when length(Headers) >= MaxHeaders ->
error_terminate(400, State);
wait_header(Buffer, State=#state{socket=Socket, transport=Transport,
until=Until}, M, P, Q, V, H) ->
case recv(Socket, Transport, Until) of
{ok, Data} ->
parse_header(<< Buffer/binary, Data/binary >>,
State, M, P, Q, V, H);
{error, timeout} ->
error_terminate(408, State);
{error, _} ->
terminate(State)
end.
parse_header(<< $\r, $\n, Rest/bits >>, S, M, P, Q, V, Headers) ->
request(Rest, S, M, P, Q, V, lists:reverse(Headers));
parse_header(Buffer, State=#state{max_header_name_length=MaxLength},
M, P, Q, V, H) ->
case match_colon(Buffer, 0) of
nomatch when byte_size(Buffer) > MaxLength ->
error_terminate(400, State);
nomatch ->
wait_header(Buffer, State, M, P, Q, V, H);
_ ->
parse_hd_name(Buffer, State, M, P, Q, V, H, <<>>)
end.
match_colon(<< $:, _/bits >>, N) ->
N;
match_colon(<< _, Rest/bits >>, N) ->
match_colon(Rest, N + 1);
match_colon(_, _) ->
nomatch.
parse_hd_name(<< C, Rest/bits >>, S, M, P, Q, V, H, SoFar) ->
case C of
$: -> parse_hd_before_value(Rest, S, M, P, Q, V, H, SoFar);
$\s -> parse_hd_name_ws(Rest, S, M, P, Q, V, H, SoFar);
$\t -> parse_hd_name_ws(Rest, S, M, P, Q, V, H, SoFar);
?INLINE_LOWERCASE(parse_hd_name, Rest, S, M, P, Q, V, H, SoFar)
end.
parse_hd_name_ws(<< C, Rest/bits >>, S, M, P, Q, V, H, Name) ->
case C of
$\s -> parse_hd_name_ws(Rest, S, M, P, Q, V, H, Name);
$\t -> parse_hd_name_ws(Rest, S, M, P, Q, V, H, Name);
$: -> parse_hd_before_value(Rest, S, M, P, Q, V, H, Name)
end.
wait_hd_before_value(Buffer, State=#state{
socket=Socket, transport=Transport, until=Until},
M, P, Q, V, H, N) ->
case recv(Socket, Transport, Until) of
{ok, Data} ->
parse_hd_before_value(<< Buffer/binary, Data/binary >>,
State, M, P, Q, V, H, N);
{error, timeout} ->
error_terminate(408, State);
{error, _} ->
terminate(State)
end.
parse_hd_before_value(<< $\s, Rest/bits >>, S, M, P, Q, V, H, N) ->
parse_hd_before_value(Rest, S, M, P, Q, V, H, N);
parse_hd_before_value(<< $\t, Rest/bits >>, S, M, P, Q, V, H, N) ->
parse_hd_before_value(Rest, S, M, P, Q, V, H, N);
parse_hd_before_value(Buffer, State=#state{
max_header_value_length=MaxLength}, M, P, Q, V, H, N) ->
case match_eol(Buffer, 0) of
nomatch when byte_size(Buffer) > MaxLength ->
error_terminate(400, State);
nomatch ->
wait_hd_before_value(Buffer, State, M, P, Q, V, H, N);
_ ->
parse_hd_value(Buffer, State, M, P, Q, V, H, N, <<>>)
end.
%% We completely ignore the first argument which is always
%% the empty binary. We keep it there because we don't want
%% to change the other arguments' position and trigger costy
%% operations for no reasons.
wait_hd_value(_, State=#state{
socket=Socket, transport=Transport, until=Until},
M, P, Q, V, H, N, SoFar) ->
case recv(Socket, Transport, Until) of
{ok, Data} ->
parse_hd_value(Data, State, M, P, Q, V, H, N, SoFar);
{error, timeout} ->
error_terminate(408, State);
{error, _} ->
terminate(State)
end.
%% Pushing back as much as we could the retrieval of new data
%% to check for multilines allows us to avoid a few tests in
%% the critical path, but forces us to have a special function.
wait_hd_value_nl(_, State=#state{
socket=Socket, transport=Transport, until=Until},
M, P, Q, V, Headers, Name, SoFar) ->
case recv(Socket, Transport, Until) of
{ok, << C, Data/bits >>} when C =:= $\s; C =:= $\t ->
parse_hd_value(Data, State, M, P, Q, V, Headers, Name, SoFar);
{ok, Data} ->
parse_header(Data, State, M, P, Q, V, [{Name, SoFar}|Headers]);
{error, timeout} ->
error_terminate(408, State);
{error, _} ->
terminate(State)
end.
parse_hd_value(<< $\r, Rest/bits >>, S, M, P, Q, V, Headers, Name, SoFar) ->
case Rest of
<< $\n >> ->
wait_hd_value_nl(<<>>, S, M, P, Q, V, Headers, Name, SoFar);
<< $\n, C, Rest2/bits >> when C =:= $\s; C =:= $\t ->
parse_hd_value(Rest2, S, M, P, Q, V, Headers, Name, SoFar);
<< $\n, Rest2/bits >> ->
parse_header(Rest2, S, M, P, Q, V, [{Name, SoFar}|Headers])
end;
parse_hd_value(<< C, Rest/bits >>, S, M, P, Q, V, H, N, SoFar) ->
parse_hd_value(Rest, S, M, P, Q, V, H, N, << SoFar/binary, C >>);
parse_hd_value(<<>>, State=#state{max_header_value_length=MaxLength},
_, _, _, _, _, _, SoFar) when byte_size(SoFar) > MaxLength ->
error_terminate(400, State);
parse_hd_value(<<>>, S, M, P, Q, V, H, N, SoFar) ->
wait_hd_value(<<>>, S, M, P, Q, V, H, N, SoFar).
request(B, State=#state{transport=Transport}, M, P, Q, Version, Headers) ->
case lists:keyfind(<<"host">>, 1, Headers) of
false when Version =:= 'HTTP/1.1' ->
error_terminate(400, State);
false ->
request(B, State, M, P, Q, Version, Headers,
<<>>, default_port(Transport:name()));
{_, RawHost} ->
try parse_host(RawHost, false, <<>>) of
{Host, undefined} ->
request(B, State, M, P, Q, Version, Headers,
Host, default_port(Transport:name()));
{Host, Port} ->
request(B, State, M, P, Q, Version, Headers,
Host, Port)
catch _:_ ->
error_terminate(400, State)
end
end.
-spec default_port(atom()) -> 80 | 443.
default_port(ssl) -> 443;
default_port(_) -> 80.
%% Same code as cow_http:parse_fullhost/1, but inline because we
%% really want this to go fast.
parse_host(<< $[, Rest/bits >>, false, <<>>) ->
parse_host(Rest, true, << $[ >>);
parse_host(<<>>, false, Acc) ->
{Acc, undefined};
parse_host(<< $:, Rest/bits >>, false, Acc) ->
{Acc, list_to_integer(binary_to_list(Rest))};
parse_host(<< $], Rest/bits >>, true, Acc) ->
parse_host(Rest, false, << Acc/binary, $] >>);
parse_host(<< C, Rest/bits >>, E, Acc) ->
case C of
?INLINE_LOWERCASE(parse_host, Rest, E, Acc)
end.
%% End of request parsing.
%%
%% We create the Req object and start handling the request.
request(Buffer, State=#state{socket=Socket, transport=Transport,
req_keepalive=ReqKeepalive, max_keepalive=MaxKeepalive,
compress=Compress, onresponse=OnResponse},
Method, Path, Query, Version, Headers, Host, Port) ->
case Transport:peername(Socket) of
{ok, Peer} ->
Req = cowboy_req:new(Socket, Transport, Peer, Method, Path,
Query, Version, Headers, Host, Port, Buffer,
ReqKeepalive < MaxKeepalive, Compress, OnResponse),
onrequest(Req, State);
{error, _} ->
%% Couldn't read the peer address; connection is gone.
terminate(State)
end.
%% Call the global onrequest callback. The callback can send a reply,
%% in which case we consider the request handled and move on to the next
%% one. Note that since we haven't dispatched yet, we don't know the
%% handler, host_info, path_info or bindings yet.
-spec onrequest(cowboy_req:req(), #state{}) -> ok.
onrequest(Req, State=#state{onrequest=undefined}) ->
execute(Req, State);
onrequest(Req, State=#state{onrequest=OnRequest}) ->
Req2 = OnRequest(Req),
case cowboy_req:get(resp_state, Req2) of
waiting -> execute(Req2, State);
_ -> next_request(Req2, State, ok)
end.
-spec execute(cowboy_req:req(), #state{}) -> ok.
execute(Req, State=#state{middlewares=Middlewares, env=Env}) ->
execute(Req, State, Env, Middlewares).
-spec execute(cowboy_req:req(), #state{}, cowboy_middleware:env(), [module()])
-> ok.
execute(Req, State, Env, []) ->
next_request(Req, State, get_value(result, Env, ok));
execute(Req, State, Env, [Middleware|Tail]) ->
case Middleware:execute(Req, Env) of
{ok, Req2, Env2} ->
execute(Req2, State, Env2, Tail);
{suspend, Module, Function, Args} ->
erlang:hibernate(?MODULE, resume,
[State, Env, Tail, Module, Function, Args]);
{halt, Req2} ->
next_request(Req2, State, ok);
{error, Code, Req2} ->
error_terminate(Code, Req2, State)
end.
%% @private
-spec resume(#state{}, cowboy_middleware:env(), [module()],
module(), module(), [any()]) -> ok.
resume(State, Env, Tail, Module, Function, Args) ->
case apply(Module, Function, Args) of
{ok, Req2, Env2} ->
execute(Req2, State, Env2, Tail);
{suspend, Module2, Function2, Args2} ->
erlang:hibernate(?MODULE, resume,
[State, Env, Tail, Module2, Function2, Args2]);
{halt, Req2} ->
next_request(Req2, State, ok);
{error, Code, Req2} ->
error_terminate(Code, Req2, State)
end.
-spec next_request(cowboy_req:req(), #state{}, any()) -> ok.
next_request(Req, State=#state{req_keepalive=Keepalive, timeout=Timeout},
HandlerRes) ->
cowboy_req:ensure_response(Req, 204),
%% If we are going to close the connection,
%% we do not want to attempt to skip the body.
case cowboy_req:get(connection, Req) of
close ->
terminate(State);
_ ->
Buffer = case cowboy_req:skip_body(Req) of
{ok, Req2} -> cowboy_req:get(buffer, Req2);
_ -> close
end,
%% Flush the resp_sent message before moving on.
receive {cowboy_req, resp_sent} -> ok after 0 -> ok end,
if HandlerRes =:= ok, Buffer =/= close ->
?MODULE:parse_request(Buffer,
State#state{req_keepalive=Keepalive + 1,
until=until(Timeout)}, 0);
true ->
terminate(State)
end
end.
-spec error_terminate(cowboy:http_status(), #state{}) -> ok.
error_terminate(Status, State=#state{socket=Socket, transport=Transport,
compress=Compress, onresponse=OnResponse}) ->
error_terminate(Status, cowboy_req:new(Socket, Transport,
undefined, <<"GET">>, <<>>, <<>>, 'HTTP/1.1', [], <<>>,
undefined, <<>>, false, Compress, OnResponse), State).
-spec error_terminate(cowboy:http_status(), cowboy_req:req(), #state{}) -> ok.
error_terminate(Status, Req, State) ->
cowboy_req:maybe_reply(Status, Req),
terminate(State).
-spec terminate(#state{}) -> ok.
terminate(#state{socket=Socket, transport=Transport}) ->
Transport:close(Socket),
ok.
